Specks of fecal matter that coagulate in your underwear over time. Usually caused by excessive flatulence, the condition is worsened when the subject showers irregularly, causing the fecal matter to harden. This often causes soreness, underwear sticking to the butt in the area and requires peeling apart of the butt cheeks before normal defecation.
Man, I drank a ton last night and ate barbeque! I've had bad gas all day, and now the crack spackle is drying and making my butthole sore!